High tension contact protection



May 28, 1935. A. BOUWERS 2,002,633

HIGH TENSION CONTACT PROTECTION F iled Aug. 21; 1931 5 \$N/T(HE5 549MB 6. INTEELOCKED To m/suzt:

CLOSl/EE l/V Pea/=51? SEQUENCE of which is adapted to rotate.

Patented May 28, 1935 HIGH TENSION ooN'rao'r' omma 'j Albert Bouwers, Emmett, Netherlands, as-

signor to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands Application August 21, 1931, Serial No. 558,578 In the Netherlands August 28, 1930 3 Claims.

This invention relates to an X-ray installation comprising an X-ray tube, the anode of which is adapted to move when in use. A common tube of this character is one the anode X-ray tubes of this kind are suitable for high loads.

According to the invention, an installation comprising such a tube also includes means operative to prevent the load current of the tube from being established when the anode stands idle.

It has been found that there is a risk of the load current of the tube being established before the anode is acted upon or moved. This is a faulty connection which may result in damage to the tube. The object of this invention is to obviate the risk referred to.

In an installation according to the invention an impediment for the passage of the load current may be done away with by closing a switch operative to establish a current for acting on the anode to move or rotate the same. A very simple embodiment of this method is constituted by an arrangement in which the primary current of a transformer for supplying the X-ray installation flows across the abovementioned switch. 1

In order that the invention may be clearly understood and readily carried into effect it will be described more fully, with reference to the accompanying drawing in which the single figure is a schematic diagram showing one form of an arrangement according to the invention. It will be evident from this description that many variations are possible without it being necessary to set out all possibilities.

Referring to the diagram shown, I designates an X-ray' tube comprising an incandescent cathode and an anode to be rotated in use. The tube is supplied from a transformer 2. A magnet winding 3 surrounding the tube and consti- .tuting an electro-magnetic stator serves to rotate the anode. In the embodiment shown, a three-phase winding is supplied from a threephase alternating current circuit 4. It is, of course, obvious that a diiferent kind of current by means of which a rotary magnetic field can be set up may be resorted to.

The current for rotating the anode is established by means of a triple-pole switch 5. As the primary current ofthe transformer 2 has to flow through the switch 5, the latter, when open, constitutes an impediment for the passage of the said current and this impediment is done away with by energizing the magnet coil 3.

After the switch 5 is closed, the primary current may be established by closing a switch 6. The primary of the transformer has connected in series with it a resistance 1 which serves initially to induce in the transformer a low voltage sufiicient to heat the incandescent cathode of the X-ray tube without there being a substantial emission of X-rays. Such emission is not brought about until after the switch 8 is closed so that the resistance 1 is shunted and full operating voltage applied to the transformer 2 and to the X-ray tube.

If it isalso desired to avoid the risk of the switch 5 being connected into the circuit with the switch .6 closed, the latter switch, as indicated in the drawing, may be coupled mechanically, or electrically to the first mentioned switch so that it is impossible for the switch 6 to be closed unless the switch 5 is closed or to prevent the switch 5 being closed unless the switch 6 is open. Such interlocking of two distinct switches to insure a desired sequence of operation thereof is comonly known in electro-technical uses and'for this reason it must be considered redundant to give a more detailed description.

What I claim is:

1. An X-ray installation comprising an X-ray tube having a cathode and an anode, said anode being adapted to be moved during the operation of the tube, an electro-magnetic stator for imparting motion to the anode, a source of high tension, an output circuit and an input circuit therefor, said output circuit including said X-ray tube, and a switching device in said input circuit, a stator circuit for energizing said stator, and a switching device in said stator circuit, said second switching device having two positions, in one position closing the stator circuit and in the second position interrupting both the stator circuit and the said input circuit, said stator circuit including a continuous conductive connection, between said second switching device and said stator.

2. An X-ray installation comprising an X-ray tube having a cathode and an anode, said anode being adapted to be moved during the operation of the tube, an electro-magnetic stator for imparting motion to the anode, a source of high tension, an input circuit and an output circuit therefor, said output circuit including said X-ray tube, and a stator circuit for energizing said stator, said stator circuit and input circuit having a common section, a switch in said common section adapted to control both circuits jointly,

said stator circuit including a continuous conductive connection between said switch and said stator, and a second switch disposed in that portion of the input circuit which leads from the first switch toward the source of high tension.

3. An X-ray installation comprising an X-ray tube having a cathode and an anode, said anode being adapted to be moved during the operation of the tube, an electromagnetic stator for imparting motion to the anode, a source of high tension, an input circuit and an output circuit therefor, said output circuit X-ray tube, and a stator circuit for energizing including said said stator, said stator circuit and input circuit having a common section, a switch in said common section adapted to control both circuits jointly, said stator circuit including a continuous conductive connection between said switch and said stator, and a second switch disposed in that portion of the input circuit which leads from said first switch toward the source of high tension, said switches being interlocked to prevent the closure of said second switch while 10 the first switch is open.

ALBERT BOUWERS. 

